I've had some success converting lens distortion parameters from Adobe format to Lensfun format.
The main complication is the difference in coordinate system. This is described in the Adobe lens model doco, and I go through the details in this thread: http://forums.adobe.com/message/3382077 Here's how the conversion looks for the 2-parameter Adobe model, which maps nicely onto the lensfun poly5 model (assuming a 4:3 aspect ratio): k1, k2 and FocalLength (aka stCamera:FocalLengthX) all come from the LCP file k1', k2' are the lensfun poly5 parameters amax = 0.5 * (1 / FocalLength) atol = (4/3)/(amax * (1 + k1 * amax ^ 2 + k2 * amax ^ 4)) k1' = k1 / (atol*atol) k2' = k2 / (atol^4) [here's some R code that calculates my example: http://ouabain.org/lensfun/fit-adobe-lensfun.R ] An example LCP file: http://ouabain.org/lensfun/DMC-GF1.lcp The converted lensfun parameters: http://ouabain.org/lensfun/slr-panasonic-local.xml I compared the results of the two profiles (in Adobe Lightroom and rawstudio for lensfun), and they match well: Lightroom: http://ouabain.org/lensfun/p1010547-lr.jpg Lensfun: http://ouabain.org/lensfun/p1010547-lensfun.jpg difference: http://ouabain.org/lensfun/p1010547-diff.jpg [n.b. to calculate the difference, I first scaled down the Lensfun output, because there is a difference in the final scale/crop between Lightroom and rawstudio] Original raw file here: http://ouabain.org/lensfun/p1010547.rw2.bz2 [for the Lightroom conversion, I first used dcraw to generate a 16-bit linear TIFF, rather than let Lightroom convert the RW2 file directly -- otherwise Lightroom will apply the 'standard' correction for this micro-4/3 lens] I'll have a look at the chromatic aberration and vignetting parameters next, and if that goes well try to write a generic LCP to lensfun converter. ------------------------------------------------------------------------------ Put Bad Developers to Shame Dominate Development with Jenkins Continuous Integration Continuously Automate Build, Test & Deployment Start a new project now. Try Jenkins in the cloud. http://p.sf.net/sfu/13600_Cloudbees _______________________________________________ Lensfun-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lensfun-users
